1. Field of the invention
The present invention relates to a heat sink and a method of manufacturing the heat sink. The heat sink with the heat dissipating fins of the invention is applicable to a heat sink for heat dissipating and cooling of the heat generating electronic components such as electronic devices as represented by personal computers, game devices, for example, and in addition to the heat dissipation and cooling in all the field necessary to be heat-dissipated.
2. Related Art
Semiconductor chips and the like used in various electronics devices such as personal computer, game device, audio device or the like are downsized and densely integrated so that the processing speed is remarkably improved to result in higher heat-generating density.
As a means for dissipating the heat generated by electronic devices such as personal computer, game device, audio device or the like including semiconductor chips with high heat-generating density, a fan is fixed on the electronic device to lower the temperature of the air within the box of the device, or a cooling member is attached to the heat generating device to cool the device, for example.
The cooling member comprises a heat transfer metal member, for example, a plate member, a block or the like. The heat generated by the heat generating device is received by the metal block and dissipated through heat dissipating fins attached to the metal block. Such a heat sink with fins is widely used.
In addition, the electronic device is required not only to have cooling ability by heat dissipation, but also to have a remedy means to control electric noise, thus the interior of the device is covered by a metal shield plate member. Japanese patent provisional publication No. 2001-57405 discloses a heat sink with a metal shield plate member and heat dissipating fins combined.
Conventionally, the heat sink for heat dissipation and the shield plate member are separately made, i.e., the heat sink and the shield plate member are designed to have constructions to be combined together. For the heat sink for heat dissipation, various mountain-shaped corrugated fins are widely used. Limited enveloping volume of the mountain-shaped corrugated fin enables to increase a heat dissipating surface of the fin, and realize a light weight fin. In the heat dissipation with the use of the mountain-shaped corrugated fin, the heat generated by the heat source is received by a heat transfer plate member, block or the like, and then the heat is dissipated through the mountain-shaped corrugated fin attached to the heat transfer plate member or the block.
However, since the space between the circuit board and the inner surface of the box is narrow in a thin-type electronic device, the space between the metal shield plate member and the circuit board becomes narrow, accordingly.
By means of the heat dissipating method in which the heat generated by the heat generating device is received by the heat transfer block or the like, and dissipated to a specific place or air through the heat dissipating fin, there is a problem that the metal block or the like may not be provided within the thin-type electronic device. Furthermore, when the space between the metal shield plate member and the circuit board is narrow and a consuming power of the heat generating device is large, the corresponding portion of the metal shield plate member to the heat dissipating fins of the heat sink is cut off, thus lowering the shield effect.
Furthermore, since the metal plate, block or the like is positioned in the heat path between the heat source and the heat dissipating fin and the contact heat resistance is produced between the metal plate, block or the like, the heat dissipating efficiency of the whole heat sink comes to deteriorate.